<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>棋盘格</title>
    <style>
        .container {
            width: 600px;
            height: 600px;
            border: 5px solid black;
            margin: auto;
            display: flex;
        }

        .black{
            background-color: black;
            width: 200px;
            height: 200px;
        }

        .white{
            background-color: white;
            width: 200px;
            height: 200px;
        }
    </style>
</head>
<body>
    <div class = "container">
        <div>
            <div class="black"></div>
            <div class="white"></div>
            <div class="black"></div>
        </div>
        <div>
            <div class="white"></div>
            <div class="black"></div>
            <div class="white"></div>
        </div>
        <div>
            <div class="black"></div>
            <div class="white"></div>
            <div class="black"></div>
        </div>
    </div>
</body>
</html>